I created an mvc4 web api project using vS2012. I used following tutorial to solve the Cross-Origin Resource Sharing, "http://blogs.msdn.com/b/carlosfigueira/archive/2012/07/02/cors-support-in-asp-net-web-api-rc-version.aspx". It is working successfully, and i post data from client side to server successfully.

After that for implementing Autherization in my project, I used the following tutorial to implement OAuth2, "http://community.codesmithtools.com/CodeSmith_Community/b/tdupont/archive/2011/03/18/oauth-2-0-for-mvc-two-legged-implementation.aspx". This is help me for getting RequestToken on client side.

But when i post data from client side, i got the error,
"XMLHttpRequest cannot load http://. Request header field Content-Type is not allowed by Access-Control-Allow-Headers."

It is most likely due to a cross-origin request, but it may not be. For me, I had been debugging an API and had set the Access-Control-Allow-Origin to *, but it appears that recent versions of Chrome are requiring an extra header. Try prepending the following to your file if you are using PHP:

@user2483724 that's because the asterisk allows any Origin domain, but it doesn't specify which additional headers are allowed. It just says, 'you're able to call this script from a page running somewhere else'
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Garet ClabornJun 17 '14 at 19:11